1. Field of the Invention
The invention relates to linear beam devices, and more particularly, to a liquid system for electrodes of linear beam devices.
2. Description of the Related Art
Several approaches for cooling an electrode of a linear beam device such as an inductive output tube (IOT) klystron, extended interaction klystron (EIK), coupled cavity traveling wave tube (CCTWT) and traveling wave tubes (TWT), are known. One such approach circulates cooling water around the electrodes. The water removes heat from the electrode, improving efficiency and longevity of the device.
In cases where multiple electrodes are used, such as in a multi-stage depressed electrode (MSDC) device, concerns with arcing between electrodes have led to the development of oil-cooled systems, as the dielectric nature of some oils, unlike water, will repress arcing. Otherwise, the water used has to be de-ionized and issues with corrosion, limited operating temperatures and increased maintenance and operating costs arise.
One issue with oil, which has higher viscosity than water, is bubble formation. Trapped bubbles disrupt oil flow and displace the circulating oil. This results in localized heating at the region of the trapped bubble. Hotspots are thus formed, which, if unmitigated, can lead to catastrophic failure of the device.
There is therefore a long felt need for a liquid cooling system for linear beam device electrodes which addresses the problems associated with trapped bubbles in the fluid flow circuit.